Large sample surveys routinely collect self-reported colorectal cancer (CRC) screening information. However, the accuracy of cancer screening self-report is unclear. Some have suggested that questionnaire design features (e.g., question wording and location) and data collection method (e.g., mail or telephone) may affect report accuracy. This proposal seeks funding to test the unique and interactive effects of these factors on the accuracy of self-reported CRC screening behavior by linking survey responses to medical records. Three specific aims will be pursued: Specific Aim 1: To investigate the effect of asking about future CRC screening intentions on the accuracy of subsequent self-reported CRC screening. Recent evidence suggests that asking about future intentions to get screened for cancer before the actual question about past screening behavior increases the accuracy of self-reports. Specific Aim 2: To investigate the effect of survey mode (telephone versus mail) on the accuracy of self-reported CRC screening. Past research has demonstrated that self-reports of socially undesirable behaviors such as illicit drug use differ across telephone and mail survey modes but little information exists on how telephone and mail survey respondents differ in their reporting of socially desirable behaviors such as cancer screening. Specific Aim 3: To investigate the interactive effects of asking about future CRC screening intentions and survey mode on the accuracy of self-reported CRC screening. The accuracy of self-reported CRC screening rates may be influenced by interactions between factors such as question order and mode of data collection, but little evidence of that exists. The objective of this investigation is to extend our prior work, focusing on consistency between CRC self- reports and medical records as the primary measure of accuracy. We will use a study design that will permit us to assess negative as well as positive CRC screening histories and, therefore, the degree of under- and over-reporting across question order and survey mode conditions. An underlying goal of our work is to make practical recommendations about best practices in survey design that could help improve the quality of self- reported health information. PUBLIC HEALTH RELEVANCE: Surveys have long offered critical information on health and health care use, but evidence suggests that survey self-reports can be inaccurate. If the information supplied by survey respondents is biased, the surveys may not provide useful information and may be misleading. In this study, we will test different methods of improving the accuracy of colorectal cancer (CRC) screening. Although the focus of this proposal is on CRC screening, the issues explored in this investigation are relevant to cancer screening in general and to other forms of healthy behavior.